At OP specifically, Monk isa burning trashfire of a jobone of (if not the) highest APM jobs in FFXIV. You might not be saying that the game feels so fast paced if you were playing a Caster (not saying that the role doesn't come with its own difficulties) or a tank or a healer.
I'm not an expert on WoW raiding, and obviously through this thread you'll read that there are people who have their own opinions on which raiding is "more difficult" or "better." I'm also biased, having completed all three Ultimate raids out to this point. So I will not and cannot answer either of those questions or indeed, whether XIV is faster than WoW or not. I can only communicate what I observe in and enjoy in XIV's raiding, and maybe that will help with any conclusions you'd like to draw.
From my experience, FFXIV's raid scene is scripted, but the challenge is fitting your job's rotation as optimally to that script as you can. Titan Savage will always Stonecrusher a few GCDs into the fight, and then move into Evil Earth 1, but how you and your team handle Evil Earth 1 and how you yourself fit your rotation into the mechanic itself are important.
Personally speaking, I enjoy the little optimizations you can make in challenging the mechanic: my static got to the point in E2S, for instance, where we all more or less stood max melee of the boss during every single flare. In E3S, we make a horseshoe around Leviathan when he drops the puddles before doing his double temporary current, leaving just enough space to stand between the puddle's death zone and the current's safe zone.
We knew the mechanics, we knew when they'd come and how much damage they would do. So instead of mindlessly doing the same dance week after week, we kept asking "Okay but how can we disrespect this more so our people can do even more damage?" However, I've played almost exclusively in my static; I understand that in pugs, you play as exactly to-the-script as you can, and it's a different atmosphere altogether.
Fights like Ultimate make it an endurance test on top of the script; you need to adhere perfectly to the script for 18 minutes straight in TEA, for instance, or you'll wipe the whole raid with any chance of recovering the run being low even if you have a Red Mage. It's not for everybody, of course; it's a boss rush type of mode that takes the combat system of Shadowbringers and pushes it to the boundaries and thus, any good or ill that is inherent in the combat system will likewise be brought with as well.